I grew with the first generation too but i started enjoying pokemon with Hoenn because when it released i was old enough to understand it. I'm ashamed to say that with the first generation i tried to beat misty with a charmander...(I was five years old)
First gen will always reign supreme! Nothing will ever top the experience of the first time you beat the elite 4, getting all the gym badges, and fighting and capturing Mewtwo! I played a lot on Yellow, because it was just too cool to have a Pikachu always following you.
1st ! Nothing was like this at the time, it was one of those games as a kid - you'd go to bed but wouldn't sleep just keep on playing til early hours, trying to navigate through the caves looking for your next badge or to try evolve the next pokemon in your team, or in my case! trying to catch an Abra! hah
Imma have to say first gen cause that is what I grew up with. Nothing matched playing pokemon yellow (sometimes blue) and watching the original show. I have so many memories of that amazingness